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The logic of generalization: Five principles common to experiments and ethnographies
Author(s) -
Shadish William R.
Publication year - 1995
Publication title -
american journal of community psychology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.113
H-Index - 112
eISSN - 1573-2770
pISSN - 0091-0562
DOI - 10.1007/bf02506951
Subject(s) - generalization , generalizability theory , extrapolation , ethnography , similarity (geometry) , epistemology , interpolation (computer graphics) , artificial intelligence , sociology , psychology , computer science , mathematics , social psychology , philosophy , statistics , anthropology , developmental psychology , motion (physics) , image (mathematics)
Both experiments and ethnographies are highly localized, so they are often criticized for lack of generalizability. The present article describes a logic of generalization that may help solve such problems. The logic consists of five principles outlined by Cook (1990): (a) proximal similarity, (b) heterogeneity of irrelevancies, (c) discriminant validity, (d) empirical interpolation and extrapolation, and (e) explanation. Because validity is a property of knowledge claims, not methods, these five principles apply to claims about generalization generated by any method, including both ethnographies and experiments. The principles are illustrated using Rizzo and Corsaro's interesting ethnographies as examples.